New Linear-Motion Guide Design Results in 50% Decrease in Noise Emissions
Linear motion (LM) guides equipped with specially designed nylon raceways eliminate ball-to-ball friction, attaining a 50% reduction in noise levels compared with traditional systems. According to Robert Love of THK Milton Keynes (Bradwell Abbey, UK), the LM guides have numerous potential applications within the medical device sector. "The reduction in noise emissions is a critical issue in a hospital environment," he says. "The last thing a patient wants to hear is generated noise from the equipment that is being used to perform a diagnosis. Medical scanners are but one example of the type of hospital equipment where silent operation is an important factor," says Love.
The SSR series of LM guides eliminates friction between adjacent balls by cushioning them with a lubricating oil film. The absence of metal-to-metal contact results in a 5-dB reduction in noise emissions, a 50% improvement over the company's previous line. In addition, the retainer has been designed with a wide contact area between the balls and the oil pockets, allowing smooth, high-speed ball rotation with less heat generation and longer maintenance-free operation than traditional technologies. The balls are uniformly lined and circulated, producing smooth movement with one-tenth of the torque variation of conventional systems.
According to Love, THK anticipates that a host of application fields will open up as industry becomes familiar with this refinement in LM technology. "In addition to medical equipment, SSR LM guides are well suited for cleanrooms and any other environment where low friction, long life, and low noise emissions are desired."
SSR LM Guides with rail widths of 15, 20, and 23 mm are supplied with standard blocks measuring 34, 42, and 48 mm in overall width and 57, 66.5, and 83 mm in overall length (excluding the lubricating nipples). Dynamic load-carrying capacities are 9.51, 12.5, and 20.3 kN; in static mode, the capacities are 16.5, 23.4, and 36.4 kN. Five accuracy standards are available, ranging from normal to ultraprecision.
